Sunday December 15, 2019

Here’s Why Women are More Likely to Develop Alzheimer Diseases than Men

The new studies add more evidence and potential explanations for suspected variations between how men and women develop the disease

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FILE - Dr. William Burke goes over a PET brain scan, Aug. 14, 2018, at Banner Alzheimers Institute in Phoenix, Arizona. VOA

New research gives some biological clues to why women may be more likely than men to develop Alzheimer’s disease and how this most common form of dementia varies by sex.

At the Alzheimer’s Association International Conference in Los Angeles on Tuesday, scientists offered evidence that the disease may spread differently in the brains of women than in men. Other researchers showed that several newly identified genes seem related to the disease risk by sex.

Two-thirds of Alzheimer’s cases in the U.S. are in women and “it’s not just because we live longer,” said Maria Carrillo, the association’s chief science officer. There’s also “a biological underpinning” for sex differences in the disease, she said.

Some previous studies suggest that women at any age are more likely than men to develop Alzheimer’s. Scientists also know that a gene called APOE-4 seems to raise risk more for women than for men in certain age groups.

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Poor sleep can predict Alzheimer’s Risk in elderly. Pixabay

At the same time, women with the disease in its early stages may go undiagnosed because they tend to do better on verbal tests than men, which masks Alzheimer’s damage.  The new studies add more evidence and potential explanations for suspected variations between how men and women develop the disease.

Vanderbilt University researchers found differences in how tau, a protein that forms tangles that destroy nerve cells, spreads in the brains of women compared to men. Using scans on 301 people with normal thinking skills and 161 others with mild impairment, they mapped where tau was deposited and correlated it with nerve networks — highways that brain signals follow.

They found that tau networks in women with mild impairment were more diffuse and spread out than in men, suggesting that more areas of the brain were affected.

It’s long been known that women do better on tests of verbal memory — skills like recalling words and lists. University of California, San Diego, researchers found that women did better on these skills despite similar signs of early to moderate Alzheimer’s than men.

Using scans on more than 1,000 older adults, they found sex differences in how the brain uses sugar, its main energy source. Women metabolized sugar better, which may give them more ability to compensate for the damage from dementia and make them less likely to be diagnosed with it by tests that involve verbal skills.

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They found that tau networks in women with mild impairment were more diffuse and spread out than in men, suggesting that more areas of the brain were affected. Pixabay

“The female advantage might mask early signs of Alzheimer’s and delay diagnosis,” said study leader Erin Sundermann. “Women are able to sustain normal verbal performance longer,” partly because of better brain metabolism.

At the University of Miami, scientists analyzed genes in 30,000 people — half with Alzheimer’s, half without it — and found four that seem related to disease risk by sex. “One confers risk in females and not males and three confer risk in males but not females,” said one study leader, Eden Martin.

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Researchers don’t know yet exactly how these genes affect risk — or by how much. “Some of these look like they’re tied to the immune system and we know there are differences between males and females” in how that works, said another study leader, Brian Kunkle.

Seven other genes seem to have different effect on risks in men versus women. The researchers have a National Institute on Aging grant to do an international study on nearly 100,000 people to try to validate and extend the results. (VOA)

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Walking, A Key Tool Identify The Specific Type of Dementia

Researchers have found that walking may be a key clinical tool in helping doctors accurately identify the specific type of dementia

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The suffering that comes as a consequence of this disease is enormous. Pixabay

Researchers have found that walking may be a key clinical tool in helping doctors accurately identify the specific type of dementia a patient has.

Published in the Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, the research have shown that people with Alzheimer’s disease or Lewy body dementia have unique walking patterns that signal subtle differences between the two conditions.

The study also shows that people with Lewy body dementia change their walking steps more – varying step time and length – and are asymmetric when they move, in comparison to those with Alzheimer’s disease.

“The results from this study are exciting as they suggest that walking could be a useful tool to add to the diagnostic toolbox for dementia,” said study lead author Riona McArdle from the Newcastle University in the UK.

“It is a key development as a more accurate diagnosis means that we know that people are getting the right treatment, care and management for the dementia they have,” she added.

For the study, researchers analysed the walk of 110 people, including 29 older adults whose cognition was intact, 36 with Alzheimer’s disease and 45 with Lewy body dementia.

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Dementia is a rapidly growing public health problem throughout the world. VOA

Participants moved along a walkway – a mat with thousands of sensors inside – which captured their footsteps as they walked across it at their normal speed and this revealed their walking patterns.

People with Lewy body dementia had a unique walking pattern in that they changed how long it took to take a step or the length of their steps more frequently than someone with Alzheimer’s disease, whose walking patterns rarely changed.

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When a person has Lewy body dementia, their steps are more irregular and this is associated with increased falls risk.

Their walking is more asymmetric in step time and stride length, meaning their left and right footsteps look different to each other.

The study found that analysing both step length variability and step time asymmetry could accurately identify 60 per cent of all dementia subtypes – which has never been shown before. (IANS)